Alexander shiels



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(No Model.) I A. SHIBLS. VACUUM REGULATING APPARATUS FOR MILKINGMACHINES.

Nb. 513, 24. Patented Jan. 30, 1894..

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ALSHIEL'S.

VAGUUM REGULATING APPARATUS FOR MILKING MAGHINES. No. 513,624. PatentedJan. 30,- 1894.

ms NATIONAL LIYNOQRAFHING cuMPANv.

WABHXNGYON. c. c

' 3 Sheets-Sheet 3.

A. SHIELS. VACUUM BEGULATING APPARATUS FOR MILKING MACHINES.

(No Model.)

,624. Patented Jan. 30, 1894.

THE NATIONAL urucsnnnma COMPANY.

WABHINGTONJ a. e.

Fries.

ATENT ALEXANDER SHIELS, or cLAseow, SCOTLAND.

SPECIFICATION forming part of Letters Patent No. 513,624, dated January30, 1894. Application filed June 1, 1893. Serial No. 476,243. (Nomodel.) Patented in England May 3, 1892,1l'0. 8,325.

To all whom it may concern:

Be it known that I, ALEXANDER SHIELS, M. 13., C. M., B. Sc;,asubject ofthe Queen of Great Britain, and a resident of the city of Glasgow,Scotland, have invented certain new and useful Improvements inVacuum-Regulating Apparatus for Milking-Machines, of which the followingis a specification.

The invention has been patented in Great Britain, No. 8,325, dated May3, 1892.

Thisinvention relates to milking machines, and it has for its object toregulate the vacuum pressure in such machines.

In pulsating machines, that is to say, in machines where the vaccumpressure on the teat cups, is made to rise and fall, say, by Way ofexample, from a maximum of fifteen degrees, to a minimum of fivedegrees, it is essential that the vacuum should never fall below theminimum, as, if it does so, the teat cups will not cling to the cowsteats with sutficient strength to retain them in position, should thecow jerk or move about. Also it is essential in such machines, to havethe pulsations as regular and decided, as possible. The improvedregulating apparatus, is designed to keep up a regular and steadypulsation, which shall be effective in all ordinary circumstances, andin which the vacuum is not allowed to fall so low, as to permit the teatcups to readily fall off during the milking. And in order that my saidinvention may be properly understood, I have hereunto appended threeexplanatory sheets of drawings, whereon Figure 1 is a side elevation ofthe apparatus. Fig. 2 is a front elevation of the apparatus. Figs. 3,4., 5, 6 and 8 are detail views. Fig. 7 is a section of a valve.

Referring to the drawings, the same reference letters, whereverrepeated, indicate similar or like parts.

The apparatus consists of a casing or cylinder a (see section Fig. 8)which is fitted within a hollow casting b, bolted to a bracket 0 on thestandard or pillar d. The pillars d, d carry the shaft 72., the crank ofwhich is 0011- nected to the piston rod, of the vacuum pump A. Thepillars d, d are bolted to a platform a: mounted or not, as desired, onWheels. The hollow casting b is made with two branches 1), b Fitted inthe branch b is a short pipe 11 which has fitted, on its outer end, ahose pipe connection I)", which isconnected to the reducing valve B,which again, in its turn, is connected by the pipe B, to the vacuumstorage tank or reservoir. V uum is created in this tank by theoperations of the pump A, which communicates with the tank by means ofthe pipe connection A. Fitted in the branch 11 is a pipe 12 which hasfitted, on its outer end, a hose pipe connection 19 leading to the box0. The pipe D, leads from the box 0 to the teat cups E of the milkingmachine. W'orking within the cylinder (1, is a packed piston e, thepiston rod f of which passes out through a cap a, screwed on to the topof the cylinder at. This cap, which has air holes a in it, is,preferably, screwed on to a collar a, fitted on the tubular cylinder Cb.The piston rod f, at its upper en d, passes through a guide bearing ffitted in a bracket f cast in one with the vertical standard or pillard. Pinned to a stud g on the piston rodf, is a connecting rod g, which,at its upper end, is pinned to a stud g on a disk-wheel h, carried onthe short horizontal shaft h, which is driven by the hand wheel h" andrevolves in bearings, on the top of the pillars d, d. The disk-wheel Ithas a projecting cam piece 1' on it. The revolutions of the shaft h, anddisk or camwheel it cause the piston rod f and plunger e to reciprocateup and down within the cylin der a.

The cylinder at has two large openings a a cut in it, one at each side,and these openings communicate,respectively,withthe pipes b and b Belowthe holes a a are, at each side of the cylinder, twovertical series ofsmall holes a (See also Fig. 5.) The casting b is made, at each side,with narrow tapering passage waysj and j, leading to and allowing freecommunication through the series of small holes a The object of havingthe large openings a a and the smaller openings a is to allow the vacuumfrom the pipe 19 to be gradually cut off or supplied, as the case maybe, to the pipe 79 and the cups. Instead of having the series of holes0. the cylinder may be cut, at each side, with a narrow tapering slot,in the manner shown at Fig. 6.

Leading from the box 0 is a pipe Z, which is connected to avacuumreducing valve m,

(Not shown.) Vac- (see Fig. 4) the spindle m of which has on it a cupleather piston m which is open to atmospheric pressure on its underside. The weights m are attached to the lower end of the spindle m Thevalve, which is a balanced one and consists of two rubber disks m mfitted on the spindle m is so arranged, that, as long as the vacuumwithin the pipe Z 1s above the minimum vacuum pressure, the suction onthe piston m is sufficient to pull up the plston, against the action ofthe weight, and retain the valve in the open position, as shown but,immediately the vacuum reaches the minlmum, the weight overcomes thereduced vacuum, and shuts the valve. As will be readily understood, byincreasing or decreasing the weights m, the minimum vacuum pressure inthe teat cups E, and pipe Z, can be raised or lowered, at will. Leadingfrom the valve m 1s a pipe n, which carries at its upper end an airadmission valve 19. (See onlarged v1ew Fig. 2 This valve may consist ofa rubber or other diaphragm 19, having a metal collar 10 as a backing,which bears on the knife-edge seat 11. The valve is fitted at the lowerend of aspindle g, which has coiled round it a spiral spring q.

r 1s the valve casing and r openings in the casing. Air has freeadmission into the valve casing, through the openings 4 r 1s a bracket,cast on the casing r',and on this bracket is fulcrumed, at or about itscenter, the lever s, which, at one end, is pinned to the spindle q, and,onits other end, carries a roller 8, which, by the action of the springq, is caused to bear against the surface of the cam Wheel 72. Therevolutions of the cam wheel h, at certain intervals, through the actionof the cam surface 't', presses down the roller 8', and, as aconsequence, pulls up the spindle q, and opens the valve 19, against theaction of spring q.

Jointed to the pipe b is a bent pipe connectlon t, which Iterm thejunction pipe, and which has fitted on it an automatically actmg valveu. The pipe t communicates with the pipe 5 at one side of cylinderaandwith the pipe b at the other. The valve u may be of any suitableconstruction, but is preferably of the construction shown at Fig. 3. Itconsists of a rubber disk u secured to a spindle n On the lower end ofthe spindle is a double cup-leather piston n which is open toatmospheric pressure on its under side. This piston is lubricated by oilsupplied from the oil cup u down the tube 11, and along the passage 1%.The lubrication of the cup leather piston reduces friction and keeps thecupleathers soft.

u are weights which are attached to the bottom of the spindle w. Thisvalve, which acts in an opposite manner to the valve m, is so arrangedthat the suction within the branch t of pipe 6, is sufficient toovercome the weight u and keep the valve closed, so long as the vacuum,within said pipe 15 and its connections b b", O, D and E, is'at or abovethe minimum, but, whenever the vacuum is reduced below the minimum, theweight overcomes the suction, opens the valve and supplies vacuum fromthe pipe 11 by the branch 25? to the branch t and connections until thevacuum again reaches the minimum, When it automatically closes.According as the minimum vacuum is altered by the altering of theweights m of the valve m, so the weights u must be altered to correspondthereto. The valve u is shown open at Fig. 3 although it is normallyheld closed when the apparatus is working.

a is the valve seat.

The action of the apparatus is as foll0ws: Presumiug that the parts arein the position shown on the drawings, Figs. 1 and 2, and that themaximum vacuum or suction pressure is acting upon the teat cups, andthat there is a free passage along the pipes b b b b, B to the vacuumstorage tank, then, when the shaft h is turned toward the left, theconnecting rod 9 and the piston rod f, is forced downward, therebyforcing down the long packed-piston 6, toward the bottom of the cylinder0., and gradually cutting off the vacuum from the pipe 19 and teat cupsE, and reducing the vacuum at said teat cups to the minimum. When thepiston is caused to rise again, by the continued revolution of the camwheel h, the vacuum is again gradually supplied until the piston reachesthe top of its stroke, when the maximum vacuum is again reached. In thismanner, the piston is caused to reciprocate up and down, and cause thevacuum pressure to pulsate, i. e. to gradually rise from the minimum tothe maximum pressure, and then gradually fall again. As the vacuum inthe pipe connection 72 leading to the teat cups, falls very gradually,it is possible, or may happen, that the vacuum may not fall to theminimum before the piston or plunger e again rises after havingcompleted its downward stroke. To obviate this and to have thepulsations as regular and decided as possible the valves m,10, areprovided. When the piston 6 has traveled so far, on its downward stroke,as to just overlap the lowest holes a the cam t' is, at the same time,just bearing on and depressing the roller 8', and, as the pistondescends, it eventually fully depresses said roller, consequentlylifting the valve 19 elf its seat and allowing air to gain access to theinterior of the pipe at, and reducing valve m. Should the vacuum withinthe pipe land teat cups not have fallen down to the minimum, before thepiston e again rises, then the air passes through the valve on andreduces the vacuum to the minimum limit when, as before explained thevalve an, automatically closes and cuts off further air ingress so thatthe minimum vacuum pressure is maintained at the teat cups until thepiston e'rises sufficiently on its upstroke, to again supply the maximumvacuum to said teat cups. Should the vacuum at the teat cups, at anytime, fall below the minimum from any cause, then the valve u comes intoaction, in the manner hereinbefore explained, and automatically suppliesdirectly and independently of the action of the piston 6 sufficientvacuum from the pipe 19 and storage tank to make up the deficiency.

As will be seen with this apparatus regular and decided vacuumpulsations are always insured.

Instead of using the reducing valves m and u, the valves such as that atm Fig. 7 may be employed. This valve consists, preferably, of a rubberdiaphragm w fitted on a spindle U), which works through a perforatedguide plate 10 This guide plate, which is screwed on its periphery,works in the internal screwthread 10 cut in the valve casin g and can beadjusted by being screwedup or down so as to regulate the tension of thespring wflwhich, at one end, bears against the back of the valve, and,at the other end, against the plate 20 If the valve 03 is used in lieuof the valve m the action is precisely the same as said valve exceptthat the diaphragm w is closed on its seat so long as the air admissionvalve p is closed, but the diaphragm valve w opens, whenever the airadmission valve p is opened so as to reduce the vacuum in the pipe Z tothe minimum, and, when this has been done, the action of the spring 20closes the valve automatically. The spring 20 in this case, acts in thesame manner as the weight on, (Fig. 1,) and is of such power as toprevent the valve opening when the vacuum at Z is at or below theminimum.

Having now fully described my invention, What I claim, and desire tosecure by Letters Patent, is

1. In a pulsating milking machine, the suction or vacuum pipe, the meansfor varying the vacuum pressure therein and an automatic valve incommunication with the vacuum pipe for reducing at certain times thevacuum pressure at the teat cups, substantially as described.

2. In a pulsating milking machine the suction or vacuum pipe, the meansfor varying the vacuum pressure therein, and an automatic valve forsupplying vacuum pressure to the teat cups whenever the vacuum at theteat cups falls below the minimum.

3. In pulsating milking machines the combination of the suction orvacuum pipe having teat cups, the means for varying the pressure in saidpipe to produce the pulsations, an automatic valve communicating withsaid pipe for reducing the vacuum at the teat cups to the minimum atcertain times, and a second automatic valve for supplying vacuum to saidteat cups when the vacuum falls below the minimum, substantially asdescribed.

4. In combination in a pulsating milking machine, the suction or vacuumpipe, the movable part e with means for reciprocating the same to varythe vacuum pressure in the vacuum pipe, the vacuum reducing valve on incommunication with the vacuum pipe for reducing the vacuum therein atcertain t mes and the means for operating said valve synchronously withthe reciprocation of the movable part e, substantially as described.

5. In combination, in a pulsating milking machine, the teat cups, thepipe connected therewith through which the suction is produced by theexhaust apparatus, and the means for varying the suction pressure tosecure the pulsating action consisting of the cylinder, a, connectedwith the suction pipe and having ports leading to said pipe and thepiston with means for reciprocating the same in the cylinder to vary thesize of the ports, substantially as described.

6. In combination in a pulsating milking machine, the suction pipe, thecylinderaconnected therewith and having the large ports a of and thereduced ports and the piston 6 with means for'reciprocating the sameover the large and small ports, substantially as described.

7. In combination in a pulsating milking machine the suction pipe thecylinder at having the large and small openings, the piston with meansfor operating it in the cylinder and the casting b supporting thecylinder and having the tapered passage ways j 3'', substantially asdescribed.

8. The combination with the pulsating cyl inder d, of branch pipes b band junction pipe 15 having a vacuum supply valve a fitted thereon,substantially as herein'oefore set forth.

9. The combination with the pipe (Z) communicating with the teat cups,of a reducing valve m fitted in connection therewith and an airadmission valve 10 fittedin connection with said reducing valve andoperated synchronously with the reciprocations of the pulsating pistonof the machine, substantially as set forth.

10. In combination the suction pipe, the vacuum reducing valve m incommunication therewith, the pipe connection n, the air valve fittedtherein, the spring for holding said valve normally closed and the levers, and cam wheel for lifting the valve at certain times substantially asdescribed.

In witness whereof I have hereunto signed my name,at Glasgow, Scotland,this 28th day of February, 1893.

ALEXANDER SI-IIELS.

Witnesses:

H. D. FITZPATRICK, WILLIAM FLEMING.

